In the generation and delivery of energy sources, including heat and electricity, to both small users in residential markets and large users in industrial markets, the control of pollution products, improved energy efficiency, and cost-effectiveness are increasingly acute concerns.
Prior attempts to address these concerns have typically involved large-scale, capital-intensive equipment and processes. For example, the prior art has endeavored to control pollution by using complicated equipment or cleaner-burning fuels at large energy facilities. Similarly, efficiency gains, which decrease primary energy consumption, have been realized through the staging of processes and the combining of energy cycles (e.g., large combined-cycle power plants).
In larger industrial and commercial facilities, cogeneration systems have been used to provide the combined benefits of generating electrical energy on-site and being able to recover and use by-product heat energy. However, such prior art technologies have generally not been cost-effective in small-scale systems. For example, fuel cell technologies offer exceptional efficiency and environmental benefits, but the high cost of fuel cell stacks in low-volume production and the complexity of systems packaged with individual, discrete components have continued to prevent this technology from becoming cost-competitive. Larger scale systems have been developed in an attempt to decrease the impact of system complexities, but increased capital risk per unit of these plants has prevented sufficient demonstrations to verify benefits and improve durability and therefore has prevented high-volume production of such systems. In addition, relatively simple, small-scale fuel cell units which use pure hydrogen as a fuel source show some benefits, but the high cost of pure hydrogen and the lack of an extensive hydrogen distribution infrastructure have limited this approach.
Representative of the prior art is U.S. Pat. No. 3,516,807, in which a reaction chamber is provided with a mixing tube fed with air that has been heated in the exit of a combustion chamber. One of the purported objectives of this structure is to provide free hydrogen for use in a fuel cell. The structure relies, however, on a ducting or path arrangement which is likely to cause carbon or other kinds of deposits which will tend to rapidly accumulate and, consequently, retard or even stop the combustion process. This and other prior art devices have also typically failed to efficiently utilize the by-product heat from hydrogen production or to produce a sufficient quantity of electrical current as to be commercially usable.
Furthermore, attempts to address these problems, as well as others inherent in the use of non-polluting fuels, have often resulted in much greater expense in terms of the converting apparatus and the by-product handling equipment. The use of non-polluting or low-pollution-generating fuels has similarly resulted in much greater equipment expense, as well as more cumbersome controls than could be efficiently marketed to both industrial and residential users.
With the world's increasing population and improving standard of living, the need for electricity and heat is expected to grow substantially. Provision of such increased energy demands using the prior art's large central facilities and massive distribution infrastructures would be exceedingly capital-intensive. The availability of a small-scale, cost-effective, and non-polluting integrated power module capable of providing both electricity and heat using existing fuel sources can eliminate the need for massive capital investments in infrastructure and electric distribution facilities while incrementally providing the energy needs of developing populations.